Gas-check pad for gun breech-blocks and process of making same.



' I The pad that constitutes the -Inent o fthe well-'lmown de Bange gas. check ings are not quite tight.

Now* according to'the present invention f srArEs PATENT oFFIoE.

nimm scnNIDEn orf'nh cnnuzow,

. 'oas-'CHECK PAD-Fon eUn'BaEEcn-'Btocxs vArm rn'ocnss oF Mannesmann.

for-` Gun Breech-Blocks and Processes of.

Making Same, which is fully set'forth inthe following specification.

plaetic eleis generally composed of fa core formed of a'mixture of;y asbestos and tallow' i'nclosedv in a casing of fabric or cloth.

The checkjring pads 'of that kind Vhave considerable drawbacksz their volume* increases .underI the influence 'of heat, the 'expansion being often suchV as to producerapidly an .inconveniencein the workingof the breeeh'blocks, while on the other hand, `after a prolonged period of firing, they lose apart of their 'I tallow, v withthe result ,that the Jolnting becomes defective and the casings 'are/cut andburn. A

It hasbeen ,y attempted to remedythose "drawbacks byfemploying in placev of rthe tal1ow,.a 4grease yproduced' by saponifying colzaoil with soda. This greasy substance, when mixed with'the asbestos, has the ldrawback of being soluble in Water, which cir- 'cul'ns'tan'cerenders the preservation of the pads very diicult, especially the gas check pads are madeofa peculiar `Substance which, while being as plastic as the usual materials hitherto employed, hasl not the drawback of swelling or hardening durir'lg the yring nor' of deteriorating .rap-4 'idly under the action ofmoisture.

Thisl new substance consists of asbestos .impregnated with a soap that is insoluble in water,su`ch as for -instance a lime soap mixed' withvaseline or equivalent fatty substance, the impregnation of the asbestos with the insoluble soap being facilitated by' .dissolving the soap in ether or any other suitable solvent. j

The insoluble soap is preferably a lime soap', but it may also be a soap having as its basis baryta, magnesia, or a metalsuch as f .then the ether is evaporated without exceed- Awholly or partially a natural fatty substance (such as oil, grease, orwax) by the corresponding metallic oxid, or by double decomposition between an aqueous solution ScHNEnmn, acitizen' ofthe Republic of France, residing when the cas- Application med December a; 191e.*serenita- 1s6,119: r

of ordinary' soap (soda soa-p or-potashv soap) anda soluble salt ofthe selected metal. The

resulting soap may then be' 'mixed with va' determined excess of a fatty substance. "This vfatty substance is, preferably vase line;but` the latter mayjbe replaced Wholly or partly by. heavy oils-off' petroleum, .shaleor coal. tar, or by para-Hin, ceresi-n, etc., or bya mixture of these substances.

VThe following isv a descriptionzoff the pre l f S'pec'cation of Iletters Patent. I Babaji-,d i111@ 1 2, 'A i -ferred process -vof preparation and the con stitution of the improved lgas checkt pads.

The pads formed of a mixture. of limel and vaseline' are made as. follows: lime soap 1s made' by' pourlng lnto -a vessel ordinary 'colza' oil and about '13% of powdered slaked L'lime. This mixture is heated for -about'two hours, being frequently agitated for the pur- `posel of facilitating 'saponificatiom and the temperature of the heating. being suiiciently ih to insure that the mixture shall remain su ciently fluid during-the w'h'ole of the operation. When it is considered that the saponiica-tion is complete, the impurities and more particularly' any unconbined lime, is

' removed by skimming.v

The percentage of lime in the resulting soap 'should be about 8%. It may be vdetermined by titration. "If the percentage is too great,"the requisite quantity of colza o1 l 1s` r added, when the-whole is'melted again with stirring The lime soap of the desired percentage, after being suitably cooled,l is dissolved in a suitable solvent in order that the asbestos.

fibers shall become completely impregnated with the soap. It is preferred to use ether as the solvent, in the proportion of about one and a half liters to one kilogram of plastic material to be made. Other solvents, such as petroleum ether or petroleum spirit or petrol, or even benzin may be used..

The solution is passed through a metal cloth for the purpose of separatlng out the insoluble portion -To this solution there vis added asbestos in' A vquantityjo'ur times the weight of thatof the lune soap. The asbestos and the soap solutionare mixed very intimately together, and

ing a temperature of 60 C.

IlThe block 'of' material 'thus formedyis crumbled, for instance by rubbing-it on cotton carding cards; then' the crumbled `mixl ture is mixed with vaseline.;

4 fluted on the The vaseline may also be incorporated at the same time as the soap, by dissolving the two substances together in ether and then adding the asbestos. driven off by evaporation.

In order that the fectly homogeneous, out bit by bit. Alternate layers ofthe material and vaseline'are applied one on top vof i the other, and the mixture is intimately kneaded together after each addition of ma- `terial and vaseline. v

The process of making a gas check pad for n breech blocks from the plastic material ereinbefore described, may be as follows A strip of annealed metal cloth is cut and proper sides, and placed in the finishing die. f

The pad, preferably roughly shaped at its edges, is placed in lthe die, the iutes are pressed down and finally nailed down. The pad is then subjected to the final compression.

Having now described my invention, what I claim as new and desire to ters Patent is 1. A gas check pad for guns comprising asbestos, water-insoluble soap incorporate therewith and a fatty substance to impart plasticity thereto. v

2. A gas check pad for guns' comprising asbestos, lime-soap-and a fatty substance to impart plasticity thereto.

3. A gas check pad for guns comprising asbestos, lime-soap and vaseline to' impart plasticity thereto.

4. A gas check pad for guns comprising 804 parts of asbestos, 20 parts of colza-011 lime-soap containing about 8 per cent. of lime and a fatty substance to impart plasticity thereto. v

The ether is finallyl lmixture shall be perthe'process is carriedA secure by Let- 5; The process of making gas check pads for guns consisting .in impregnati'n asbestos with ai water-insoluble soap dissoved in a volatile solvent, evaporating-oif thesolvent and then incorporating the product in successive small portions into vaseline to-render the mass plastic'. f

6. The process of making gas check pads for guns consisting in impregnating'asbestos with a water-insoluble soapl dissolved in a volatile solvent, evaporating off the solvent and then incorporating theproduct in successive small portions into a fatty body to render the m'ass plastic. j

7. The process of making gas .check pads for guns consisting in impregnating asbestos with a water-insoluble soap and vaseline dis# solved in a volatile solvent and then evapo rating the solvent;

8. The process of :making gas check pads for guns consisting in impregnating asbestos with colza-oil lime-soap dissolved in ether, evaporatin off the ether and mixing the product with vaseline to plastic.

9. The process of making gas check, pads consisting inincorporating asbestos with colza-oil limesoap prepared by heating colza-oil with about 13% of its wei ht of slaked lime, combining the excess 'o lime with additional colza-oil to reduce the lime in the soap to about 8% and then mixing the product with vaseline to render theI pad plastic.

In testimony whereof I -have signed this specification in the presence of two subscribing witnesses. y

EUGENE SCHNEIDER.

Witnesses:

CRAs. P. PREssLEY, ANDR Mos'rrcirmir.-

render the pad 

